A photodiode carrier is a part on which a photodiode is mounted, and which is used built into the inside of the optical receiver module for the optical communication. FIG. 7A is a top view of such photodiode carrier, and FIG. 7B is a front view of the photodiode carrier. In the photodiode carrier, four pairs of a signal side electrode 102 and bias side electrodes 103 to 106 are formed on a ceramic substrate 101. The signal side electrodes 102 are arranged in parallel each other on one main surface of the ceramic substrate 101 respectively, and are formed so that they may extend to the upper surface of the ceramic substrate 101. The bias side electrodes 103 to 106 are also arranged on the main surface of the ceramic substrate 101, and are formed so that they may extend to the upper surface of the ceramic substrate 101 after being drawn around.
FIG. 7C is a front view in the state that a photodiode 111 is mounted on the photodiode carrier. FIG. 7C shows the state in which the photodiodes are mounted by flip chip on the photodiode carrier such that the electrode surface of the photodiodes face the photodiode carrier side. Here, an example is shown in which a back face incidence type quadruple photodiode array is used as the photodiode. Four pairs of signal side terminals and bias side terminals are also formed on the electrode surface of the back face incidence type quadruple photodiode array. By the flip chip mounting, these electrodes are connected to electrodes on the photodiode carrier side, respectively.
FIG. 8 is a side view showing the state in which the photodiode carrier with the photodiode mounted shown in FIG. 7C has been built into an optical receiver module. The photodiode carrier with the photodiode mounted is fixed on the lower step part 113L of a step carrier 113 with multilevel, and a preamplifier 114 is fixed on the upper step part 113U, respectively. By wire bonding, a signal side electrode in a photodiode carrier surface is connected to the preamplifier 114. Not being illustrated, a bias side electrode on a photodiode carrier surface is also connected to the ground in an alternating current manner by being connected to a chip condenser on the upper step part of the step carrier. Depending on the incident light to an optical receiver module, the quadruple photodiodes output the output signal, which is amplified by the preamplifier 114 and is outputted, respectively.